Red blood cells or erythrocytes are the most common type of red blood cells and the organism's principle means for delivering oxygen to the human body tissue through the bodies' circulatory system. The red blood cells take up oxygen in the lungs and release it while squeezing through the bodies capillaries. Thus, they are a vital part of the human life.
The loss of blood during surgery and as a result of motor vehicle and other accidents, crime, war and natural disasters have created a continuing large demand for donor blood. Therefore, numerous blood banks and donor programs have been established by the Red Cross and other organizations. Nevertheless, there are times, particularly in time of a natural disaster when there are shortages of blood in the region of a disaster.
Another problem associated with donor blood is its shelf life. Collected or donor blood is usually stored as separate components and some components have short shelf life. For example, there are no storage solutions to keep platelets beyond seven days. Red blood cells, the most frequently used component, has a shelf life of 35 to 42 days at refrigerated temperatures. This limited shelf life makes it difficult if not impossible to have a stockpile of red blood cells for a natural disaster or an unusual demand for a particular blood type as for example “O” types.
Over the past 20 years there have been a number of approaches for extending the shelf life of red blood cells. For example, a U.S. Pat. No. 5,030,200 of Judy et al. discloses a method for eradicating infectious biological contaminants in body tissues. As disclosed, the method eradicates infectious pathogenic contaminants such as enveloped viruses, bacteria, trypanosomal and malarial parasites, present in body tissues, such as blood, blood components, semen, skin, and cornea, before the treated body tissues are introduced into, or transplanted onto, the body of a human. Such method includes the steps of (1) admixing an effective non-toxic amount of photoactive compound which has selectivity for binding to the infectious pathogenic biological contaminants present therein with the body tissues outside the body to produce resulting body tissues; (2) maintaining the resulting body tissues in a suitable container; and (3) irradiating the resulting body tissues in the container for an effective period of time with an effective level of radiation. The radiation penetrates the resulting body tissues and eradicates the photoactive-compound-bound contaminants present in the resulting tissue. In essence, it produced a decontaminated body tissue suitable for introducing into or transplanting onto the body of a human.
A more recent U.S. Pat. No. 5,476,764 of Bitensky discloses a method using CO for extending the useful shelf life of refrigerated red blood cells. The method uses carbon monoxide for stabilizing hemoglobin in red blood cells to be stored at low temperatures. Changes observed in the stored cells are similar to those found in normal red cells aging in the body. The extent thereof being directly related to the duration of refrigerated storage. Changes in cell buoyant density, vesiculation, and the tendency of stored cells to bind autologous IgG antibody directed against polymerized band 3 IgG, all of which are related to red blood cell senescence have been substantially slowed when red blood cells are treated with CO. Removal of the carbon monoxide from the red blood cells is readily and efficiently accomplished by photolysis in the presence of oxygen so that the stored red blood cells may be safely transfused into a recipient.
Finally, a U.S. Pat. et al. No. 7,717,274 of Kao discloses a Device and Method for Preparing Washed Red Blood Cells for New Born Transfusions. As disclosed a newborn transfusion cell washing device generally comprises a disposable, graduated test tube shaped container having a cap with an inlet port, an injection/sampling port, a suction port, and a vent. The container is capable of being inserted into a conventional clinical centrifuge. The device requires a relatively small volume to operate, 25 ml or less per procedure and can be performed easily by any hospital blood bank technologist without any specific training. Washed red blood cells can be provided to the patient in a timely manner without the need for “fresh blood.” Any in-dated red blood cells can be washed to remove excessive potassium and other toxins. The main red blood cells aliquot can be saved and repeatedly sampled until the unit is expired or exhausted. This provides a cost savings to the hospital and more importantly, minimizes the recipient's donor exposure. Kao et al also discloses storing red blood cell products using chemical antioxidants to extend the shelf life from 35 days to 42 days.
Notwithstanding the methods above, it is presently believed that there is a need and a potential commercial market for the present invention and for a method to extend the shelf life of red blood cells by up to as much as about 66%. It is also believed that the procedure for extending the shelf life of red blood cells can be readily completed by any hospital blood bank technology without any special skills and does not require excessive cost for equipment.